> > > > About General Datum Points

To create datum points that lie on or are offset from the model geometry, use the general type of datum points. Depending on the existing geometry and your design intent, you can use different methods for specifying the point's location.
 Within one Datum Point feature, you can add points using different placement methods.
You can place a general datum point at the following locations:
On a curve, edge, or axis
At the center of a circular or elliptical entity
On a surface or quilt, or offset from a surface or quilt
On a vertex or offset from a vertex
Offset from an existing datum point
Offset from a coordinate system
At the intersection of entities. For example, you can place a point at the intersection of three planes, at the intersection of a curve and a surface, or at the intersection of two curves.
 You cannot place a datum point on the axis of a coordinate system. However, you can use an axis of a coordinate system as the offset direction.
Accessing a General Datum Point
Click Model, click the arrow next to Point, and click Point to create a general datum point.
Using the Object-Action Workflow
With certain types of datum points, you can first select feature references and then activate the Datum Points tools.
You can select the following feature references before activating the tool:
A vertex
Multiple vertices
A curve
An edge
A surface or quilt
A datum axis
A coordinate system
You can select the following combinations of entities after activating the tool:
A datum point and a coordinate system or an axis of a coordinate system
A datum point and a straight curve, edge, or axis
A datum point and a datum plane or planar surface
A vertex and a straight curve, edge, or axis
A vertex and a datum coordinate system or an axis of a coordinate system
A vertex and datum plane or planar surface
Two or three surfaces
Two edges or curves
Surface (or datum plane) and curve (or edge)
Creating a Group of Datum Points on a Surface or Quilt
You can create a group of datum points on a surface or quilt by placing multiple points on the selected reference. All points created during one operation belong to the same group.